Centrifugal pump and compressor



Ma 15, 1928. l 1,676,65

. W. W. EISENWINTER CENTRIFUGAL PUMP AND COMPRESSOR Filed May 8, 1926 Inve ntorn WLlfPed WELsenwLnten,

His Atto Pne WILFRED W. EISENWINTER, OE LYNN,

ELECTRIC COMPANY, A CORPOBATIGZT OF MASSACHUSETTS, ASSIGNOR T0 GEIQ'ERAL NEW YORK. I

CENTRIFUGAL PUMP AND COMPBESSQR.

Application filed may 8,

The present invention relates to centritugal pumps and compressors and especially to centrifugal pumps and compressors having difi'users or .discharge rings constructed in accordance with the invention of Sanford A. Moss and Manuel G. Robinson, disclosed and claimed in their Patent No. 1517,2133, granted Feb. 8, 1927. Such a diffuser or discharge ring comprises two spaced annular plates or walls between which the fluid discharged by the impeller flows outward, said plates being so close together that the angle of the fluid at normal load is greater than 25 throughout the major portion of its travel and is preferably of the order of 35. In this connection, it is pointed out that when an impeller is running, the fluid is discharged from its periphery at a con stant angle, and if the discharge takes place into a difluser formed of two circular, parallel plates, these being as guide waves between the plates, the fluid will pass outward in a spiral path from the inner to the outer plates and will maintain this constant angle, forming what is called a free vortex. By the angle of the fluid in such a case is meant the angle between the direction of a stream line at any point and the tangent to a circumference passing through that point.

In the operation of a pump or compressor embodying a difl'user ofthe above referred to type, the angle of the fluid varies w1th the quantity of fluid delivered by the impeller. If the quantity of fluid being handled increases, the angle of the fluid increases, and if such quantity decreases, the

angle decreases. Also, in a construction embodying such a diffuser, the angle of the fluid varies with the distance between the plates forming the difi'user. If the distance between the plates forming the diffuser is decreased, the angle increases, while if the distance between the plates is increased, the angle decreases. For best efficiency an angle of the fluid of the order of 35 is required. and heretofore in designing machines of this character in accordance with the Moss and Robinson invention. the.

plates forming the difluser have been spaced apart a distance such that the angle of the fluid for best efliciency obtains at normal load. As a result, the efficiency is not so good at loads other than normal. For example, if a diffuser is designed for best 1926. Serial No. 107,772.

efficiency at a particular volume of flow, then if the volume of flow decreases, the eificieney of the compressor decreases, because the angle of the fluid decreases.

The object of my invention is to provide an improved construction and arrangement in a centrifugal pump or compressor embodying a discharge ring constructed in-ac' cordance with the attire-mentioned Moss and Robinson invention, wherein the space between the walls forming the ditiuser may be varied in width whereby the pump or compressor.may be adjusted to give good etficiency at various loads.

Referring to the drawing, Fig. 1 is a side elevation, partly in section, of a motor driven compressor embodyin my invention; Fig. 2 is a sectional side view on a smaller scale of the compressor shown in Fig. l; and Fig. 3 is a detail, sectional view.

Referring to the drawing, 1 indicates a. centrifugal compressor which, in the present instance, is shown as being driven by an electric motor 2. 3 indicates the shaft of the compressor, 4 indicates the impeller, and 5 and 6 indicate the two plates which form the difi'user or discharge ring. In the present instance, an impeller is shown which receives fiuid to be pumped on oneside only, and discharges it at its periphery into the diffuser. 7 indicates theportion of the compressor casing which forms the inlet to the compressor, 8 indicates the discharge scroll for the compressor, and 9 indicates the discharge conduit. The construction so far described isto be taken as typical of any suitable centrifugal compressor provided with a difluser embodying the Moss and Robinson invention.

Now, according to my invention, I provide in connection with the diffuser means whereby the annular space between plates 5 and 6 may be adjusted so as to increase or decrease the width of the space. In the present instance, the walls forming the scroll 8 are constructed from pieces of sheet material wclded together and to the periphery edges of plates 5 and 6 and these walls have inherent resiliency tending to move plates 5 and 6 away from each other. Plates 5 and 6 are held spaced the desired distance apart by means of bolts 10 which extend through openings in the plates and have nuts 11 on their outer ends. It will be clear that by tightening nuts 11 on the bolts 10, plates 5 and 6 may be squeezed or forced towatd each other, thereby decreasing the width of the space between them, while by loosening nuts 11, plates 5 and 6 will be permitted to move awayfrom each other, thus increasing the width of the space. On the bolts are spacers 12, which serve to limit the amountwhich plates 5 and 6 may move toward each.

provide a passage having a width such as to give the most etficient angle of the fluid for any particular volume of fluid. By this means, therefore, a compressor may be operated at the same high degree of eficiency at various loads. 1

In accordance With the provisions of the patent statutes, l'have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment of my invention, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States is:'

l. A'casing for a centrifugal compressor having a discharge scroll and a diifuser comprising two spaced annular walls between which the fluid flows radially outward, char acterized by the fact that the scroll comprises resilient walls which are secured to the peripheral edges of the walls of the diffuser and that means are provided whereby; the distance between said difiuser walls may be adjusted.

2. A casing for a centrifugal compressor having a diffuser comprising two spaced annular walls between which the fluid flows radially outward, and means carried by said walls for efi'ecting adjustment of them toward and away from each'other, said means including-a discharge scroll having resilient walls secured to the peripheral edges of the diffuser walls. I

A casing for a centrifugal compressor having a diffuser comprising two spaced plates between which the fiuid'flows outward, conduit means having resilient walls connected with the plates, whereby said plates are resiliently movable therewith, and means for moving said plates with respect to each other to vary the space between vthem.

4. A casing for a centrifugal compressor having a diffuser comprising two spaced plates between which the fluid flows outward, conduit means having resilient walls connected with the plates, which walls tend to move the plates away from each other means for forcing said plates toward each other, and means for limiting the movement oi. the plates toward each other.

In witness whereof, I have hereunto set my hand this 5th day of May, 1926.

WILFRED w. EISENWINTER. 

